In radionuclide therapy using the isotope 177Lu, e.g., peptide-receptor radionuclide therapy (PRRT) of neuroendocrine tumors [1, 2] using [177Lu]Lu-DOTATOC or [177Lu]Lu-DOTATATE, or PSMA radioligand therapy (RLT) of metastatic prostate cancers [3] using [177Lu]Lu-PSMA, post-therapy dosimetry of organs and tumors is feasible based on quantitative gamma-camera or SPECT imaging of the gamma emissions from 177Lu. This evidence concerns the gene FOLH1 and metastatic prostate carcinoma.